Network Administration

Specifying TCPIP_PREFIX for OS/390

The value of the TCPIP_PREFIX environment variable used in finding configuration data sets is determined in the following way:

If the value is set by the user, either interactively or through a program, before the socket library's initial attempt to use the TCPIP_PREFIX variable to locate a data set, the library uses the value set by the user.
If the TCPIP_PREFIX variable is undefined when the socket library attempts to use it to locate a data set, the TCPIP_PREFIX variable is set with a 27-character string array in L$CNDBA in the transient library. However, the library may search the TCPIP.DATA file for the DATASETPREFIX keyword value before using the array. (See item 2 under Specifying TCPIP_PREFIX for OS/390 for search order.) The default value of this array is TCPIP. A zap that changes this default is provided with the transient library installation instructions. Some SAS/C programs received from software vendors or other sites may not use the transient library and could require their own zaps. For this reason, avoid using the zap, if possible, and instead use the ETC high-level qualifier derived from the UNIX filename or make TCPIP the default high-level qualifier.